Devices on two ends of network communications usually span multiple network layers and network management domains, and two terminal devices communicate with each other using Internet Protocol (IP). An IP packet used for communication between the two terminal devices is encapsulated in a network tunnel by a network virtualization overlay endpoint (NVE), and this tunnel actually adds an IP data packet header to the IP packet used for communication between two terminals. A network tunnel packet is carried by an Ethernet link layer or a multi-protocol label switching MPLS tunnel over the Ethernet link layer.
In the prior art, operation, administration and maintenance (OAM) technologies cannot span network layers. Moreover, OAM is terminated at a peer end of a link and cannot go beyond a boundary of its network layer. This means that, if a failure such as service interruption or communication quality degradation occurs in an end-to-end communication network, checks need to be performed using OAM at each layer and each domain, resulting in multiple independent OAM procedures.
Because there are multiple independent OAM procedures, problems of low efficiency and low accuracy are caused in a process of processing, analyzing and associating diagnosis reports among various network layers or various network management domains.